The gut, or digestive tract, is where the food we eat is broken down (digested) and absorbed into the blood. The key food groups are fats, carbohydrates and proteins; vitamins and minerals are also required for a healthy diet and of course we need water too.

Examples of foods that are mainly protein are meat, fish, pulses and soya products. Fats, including butter and oil, are found in a range of foods, such as cheese and cream. Carbohydrates are found in bread, potatoes, rice and pasta,

In this unit you will find out that the sensation of pain is caused by the release of a chemical called prostaglandin that stimulates the nerve endings and sends an electrical message to the brain. Inhibiting the formation of prostaglandin reduces pain and we will see, by looking at the specific shape of the molecules involved, how aspirin can so inhibit the formation of prostaglandin. To make the most of the material of this unit you will need to use an organic molecular modelling kit such a

In Chapter 1, Section 1.4 of the Calculator Book, you saw that multiplying a price by, say, 1.30 is equivalent to increasing it by 30%. Similarly, multiplying a price by 0.94 is equivalent to decreasing it by 6%. The figures 1.30 and 0.94 are called price ratios. In Table 6, the price of a loaf of

In this course, there have been three occasions when checks have been made to see whether the result is greater than or less than some other value. The first case was in calculating the BMI and determining whether the person was overweight or underweight; the second case was in determining whether a person was walking or running from his footprints; and the third case was in checking whether a phone had been used for more than 30 minutes. Checking whether values are greater than or less than

Between about 30 BC and AD 75 the most common type of ceramic tableware in the empire was terra sigillata (often known as Samian ware). This was a shiny red-surfaced ceramic which was first made in Arezzo in Tuscany, Italy and then widely imitated in many areas such as Campania, Rome, southern and eastern Gaul, and Asia Minor. The forms of this pottery were typically cups, bowls, plates and dishes. Beyond the areas where it was produced, the pottery was widely traded and it has been fo

In this activity you will be challenged to reinterpret the following programme extracted from the Powerdown Show DVD: Energy Descent Pathways. The reason this programme was selected, from the many audio-visual programmes currently available online that tackle environmental and social issues, was because it presents an "ecotopian" approach to tackling the converging social, econ

outline and discuss the process of systems modelling, where models are used as part of a systemic approach to a range of different situations

recognise that systems models may be used in different ways as part of a process for: improving understanding of a situation; identifying problems or formulating opportunities; supporting decision making.

The general framework of systems engineering adopted in the course consists of: a hierarchy of elements; aims associated within its outputs and process; a set of principles; a division into technical and managerial components of the process.

The lexicon of system engineering used in the course contains the hierarchy of elements:

strategy: meaning the accumulated decisions concerning the areas in which an organisation operates and its lon

The development of systems engineering was contemporaneous with that of systems analysis in public policy. Though its origins can be traced back to the 1930s and 1940s (Hall, 1962, p. 7), its more widespread application can be dated from the early 1950s. The earliest formal teaching of systems engineering was a course presented in 1950 at the Massachusetts Institute of Technology by G.W. Gilman, who was then Director of Systems Engineering at Bell Laboratories. Gilman was a strong promoter of

It can cause opinions to change on the problem situation and the issues arising from it.

It can provide an agenda for change.

In either case (though both may result), the objective of this stage is to debate, with all concerned, the changes proposed to ensure that they are both desirable and feasible. The aim is to arrive at consensus about the prop

External assessor

The cell membrane is constructed from lipids. Chemically, lipids are a rather varied group of compounds that include all the substances you might already think of as fats or oils. What they have in common is that they are all insoluble in polar liquids like water, but soluble in organic (carbon-based) solvents: by this I mean the sort of smelly solvents you tend to find in paints, glues and degreasing agents; chloroform is one example. Lipids make up the fatty components of living organisms a